T1 Flashcards
Impact of Software Crisis
Software crisis was created when the hardware developments, such as speed of RAM and
processing power, awes growing at a much faster pace than software development.
Reasons for Software Crisis
Systems were not being delivered on time/late.
Developments in software were not keeping pace with developments in hardware.
Software systems were delivered over budget.
Software systems were becoming more complex.
Systems did not meet the user requirements/system specification.
The user interface did not match the users’ IT skills.
Systems were difficult/expensive to maintain.
Off the Shelf
Can be bought directly from the author or publisher from shops, websites, mail order
catalogues or specialist magazine
Custom Built
Can be developed either In-house by existing employees or by programmers.
employed by the company to develop the software or by using an outside agency.
Main Factors affecting System Devolpment
User Needs
Time
Costs
Describe Cost
► The current system may no longer be suitable for its purpose as the requirements of the
business may have changed or the business may have expanded.
► Technical support for the old system may be no longer available.
Describe Time
► Current procedures are taking too long to produce a product.
Describe Cost
► The current system may be too inflexible or expensive to maintain.
► Technical support for the old system may be too expensive
System Analysis
Carries out a feasibility study, identifies user requirements, undertakes
Fact finding and liaises with users.
Programmer
Write the code for the specification. Tests the code during module.
Debugs the code to detect & correct the code.
Documents the code to make the code more meaningful.
Project Manager
To oversee the development of the new system, to schedule the project.
To manage the budget, to allocate resources (Resource includes human, hardware and software)
Purpose of Analysis
The main purpose of analysis is to investigate a problem with an information system.
Interview
this involves the user answering questions from the system analysis on a one-to-
one basis or in small groups. It may be structured or unstructured allowing questions to be
followed up as more facts may come to light from the users’ answers.
Questionnaire
this involves a representative group of users who complete a set of questions
which could be open or closed and aimed at identifying detail.
Observation
This involves the system analyst shadowing users carrying out a particular process,
it allows the analyst to see first-hand what the user roles are, drawback is that users may.
respond differently if being observed.
Document Sampling
This involves the analyst inspecting sample documentation such as
orders, invoices and reports to help identify the systems inputs and outputs to allow the analysis
to get an idea of the volume of data.
Describe Level 0 Diagram
AKA a context level diagram, sees the system as one main process and does not consider data stores.
Level 1DFD
Breaks down the processes into a number of subprocesses showing how data flows between them
